Hi @donat
I just tested with the German .mo file and was able to get it to work. Make sure you’ve done the following:
1.) Make sure your file is located at this exact file path: application/languages/it_IT/LC_MESSAGES/messages.mo
2.) Make sure to rename the file from translations-de_DE.mo to messages.mo
These instructions are here on the right hand side for reference: https://translate.concretecms.org
Let me know if that does the trick for you 